This might be because the sound control settings are not set correctly on your computer. You may need to make sure that the correct sound output is selected. The default device might be set to the speakers or headphones for your computer.
This setting may be in different places depending on the version of the operating system you are currently using. If you cannot find these settings in your control panel please give us or your computer manufacturer a call so we can help you find them.
Once you find these settings if "Speakers/headphones" is selected. Please change them to the MyWirelessTv device which should be labeled as "Digital Output".
This happens because typically the sound should automatically switch but sometimes it does not for some reason or another. We have included a picture of what these settings look like in our operating system but they may be different for yours.